Upgraded EVO2 gearbox

4GTuner

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Thanks guys. I'm aware of his experience and have watched all the videos he's posted. He's a madman, lol. I've been following the gear development from the beginning, in his thread over on ECMLink forums. I just wanted to get any feedback from others who have the gears. I actually just sent him the parts to have 3rd, 4th, and the CD worked. I have high hopes for these gear sets in my street car.
 
Good stuff. I hope from our positive experience at least, others can trust him to do the work and not run off with the cash lol
 
Rob - I have your centre diff housings all wrapped, packed and ready to ship, I just need to get out of work and to the post office before they close!
 
For those considering the Matthias straight cut gear option, I second Rob's feedback that Matthias has proven himself to be a trustworthy guy. I'm hoping he'll be looking at doing a straight cut 1-5 gear set now as I have my old EVO 'box sitting there with smashed guts now...... ;)
 
ENGINR said:
Rob - I have your centre diff housings all wrapped, packed and ready to ship, I just need to get out of work and to the post office before they close!
Deposited $$ into your account tonight mate. Should show up tomorrow. :thumbsup:
 
Faaaark me! Shame the cooler broke but still Congrats man, that's a blistering time and around 150mph!! awesomeness, I'm stripping a gearbox down and might get some upgraded parts from ya in the coming months just to keep on the shelf for the day I do go back to manual
 
Damn thats fast.

im out of my league here, but thats never stopped me opening my mouth before. But it looks to be a real handful at launch.
By the video it squats (that means it lifts the rear tyres up and the body falls down) then the tyres spin and the body lifts then it grips and it unloads the rear again.

I think you need to look at your rear suspension and raise the front mounts of the arms.

think of it as trying to push a fridge. At the moment you are pushing at the bottom and the fridge wants to tip over backwards. You need to push higher up on the fridge, lifting the front of the arms will do this.
i explain simply as i know some newbies may want to understand without talking of roll centres, inertia moments squat and anti squat, and such.

Feel free to tell me to piss of as you dont need my silly observations, i wont take much offence....
there is a way to test and fine tune your arm settings without even starting the engine, and in your workshop.

if you interested.
 
Ole forgetful me.
well you need to raise the roll centre of the rear end. If you have adjustable mounts on the diff, lower the arms. If its on the body, raise them.
you want to keep raising the roll centre till your launch is anti squat. You want the rear end to slightly rise at launch. This means that the rear tyres are pushing into the track not lifting off. Also it will keep weight on the front wheels. Iif you have concerns about front driveshaft strength, then a little squat will be ok.
Once the squat is sorted, if its launching to the left, you shorten the top right link a turn or so to preload it. It looks to launch pretty straight and you dont have a n/s engine twisting the car and steering it left.

i always think the dragsters would be faster if engine is e/w rather than n/s. Its such a waste turning all that power 90°. But at least they only do it once. Not twice with a transfer and a rear diff.

To set your roll centres in the shed, you need to measure your c of g height. Find a point on your roll bar at that height. Attatch a trucky chain and the other end to a wall behind car.lock brakes and Load the chain with a ratchet binder and watch to see if the rear end squats or not. Adjust arms and repeat. This method will get you close. You should get enough tension to see the squat before the car drags across ground.

My 2c.
 
There is considerations to be made about arm/link distance apart at the diff, and the height above and below diff centreline, but i dont understand that bit. Obviously the wider the arms, the less tension in the arms. And if the say top arm is lower, it will push harder on the body and the lower arm will pull correspondingly less.

It gets beyond me
 
Ok, update time.......

So after 2x dyno sessions and 6x track days (a total of approx 200km of driving - if that) the standard EVO2 5th gear was destroyed towards the end of the front straight at Winton.

This resulted in having to pull the gearbox out and apart to determine the extent of the damage. Fortunately the shrapnel from the 5th gear had not made its way through the gearbox, but the inspection uncovered something else that was very unexpected and extremely disappointing.

I've been asked for feedback on my upgraded EVO2 gearbox, so here it is.

The attached images are of the straight cut 3rd and 4th gears that I purchased. Every tooth is showing signs of pitting and wear and we suspect it's an issue with the hardness of the material used. This gearbox was run on Redline MT 75W90 gear oil as recommended and has seen no more than 200km of use, but these gears look like they have come out of a car that has done 200,000+ km.

I had already replaced this gearbox with a PPG dogbox so I was not relying on having to put this one back in the car to keep driving, but unfortunately I was hoping to sell it, to off-set some of the cash spent on the PPG.

Neither Andrew (of CVAP) or myself are comfortable with putting these gears back in the gearbox, bolting it together and selling it to the "next poor sucker" to make it their problem - that's "just NOT cricket!"

I've been offered replacement gears at a cost of approx $1200AUD (not including shipping) but cannot justify spending this kind of $$$, plus what it will cost to rebuild the gearbox, to then sell it and walk away with (hopefully) enough to cover what it cost me just to rebuild it a 2nd time!!

Not a "Happy-Chappy" at the moment.
 

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